Improvement in safety attachments to hoisting-machines



' W. 1). AN DRUMS,

Safety Attachments to Misting-Machines.

Patented March 25, 1873.

these levers.

PATENT WILLIAM D. ANDREWS, OF BRGOKHAVEN, NEW YORK.

IMPROVEMENT IN SAFETY ATTACHMENTS TO HOlSTiNG-MACHINES.

Specification forming part of Letters Patent No. 137,165, dated March 25, 1873.

To all whom it may concern.-

Be it known that I,WILLIAM D. ANDREWS,

of Brookhaven, in the county of Sufi'olk and State of New York, have invented Improvements in Safety Attachments for Hoisiiug-Machines, of which the following is a specification:

p This invention consists in the employment, in connection with the car or platform of a hoisting-machine and the guides between which the platform works, of grasping devices of novel construction, operating in connection with guides permanently and securely attached throughout their length to guidepostsupon either side of the hatchwaythrough which the car or platform passes, for the purpose of arresting the descent of the car in case the hoisting-rope should break or become suddenly slack.

In the accompanying drawing, which forms a part of this specification, Figure 1 represents a side elevation of the car and parts of the guides of a hoisting apparatus ,with my improved safety attachment applied thereto. Fig. 2 is ahorizontal section of the same.

Similar letters of reference indicate corresponding parts in both figures of the drawing.

A A are the guide-posts of a hoistway, and I) b guides rigidly attached to the inner faces thereof. B is the car, arranged to travel up and down between the fixed guide-posts A A. U is the hoisting-drum, and D the hoistingrope. A multiplication of hoisting ropes or chains may, if desired, be attached to the drum, or be passed overit as a belt, and be attached to a counterpoise for operating the hoistingrope by friction.

It will suffice here, however, to describe but a single rope, connected at its one end with the car, and at the other to the drum, which latter may be of any suitable construction.

The hoisting-rope D is connected, to produce the grasping the T-shaped, grooved, fixed guides b b, by hook-shaped lips c c rigidly secured to the platform or cab. These T-shaped or grooved guides are attached throughout their whole length to the posts A A. The safety attachment consists, in part, of levers E E, having intermediate fulcrums f f, the hoistingrope D being connected with the inner ends of Suspended from or attached to the outer ends of these leversE E are frictionblocks F F, of a wedge shape, being perpendicular and parallel with the guides b b on their faces, which are next the said guides, and inclined upon their backs, with their thinner ends upward. These friction-blocks or wedges are suspended from the levers by means of rods permanently attached to the said blocks orwedges, but passing freely through holes in the levers, nuts being applied to screw-threads on the said rods above the levers to enable the levers to raise the blocks or wedges, but the blocks or wedges being free from the levers to such extent that. the levers cannot push down the blocks or wedges. The inner arms of the levers are arranged within stump-like stops it h, which are securely attached to the upper cross-head of the car. The said blocks, when the tension is applied to the hoisting-rope, as in raising or lowering the car under ordinary circumstances, will, by reason of the then depressed position of the outer ends of the levers E E, hang free from the faces of the guides b b, and exert no friction thereon. In this position the friction-blocks F F are also free from any binding contact with the rollers G G, which are arranged be tween the inclined backs of the friction-blocks and the stationary reversed inclined surfaces H H which are'provided on the car, the said surfaces being parallel with the inclined backs of the blocks F F the rollers G G being supported in position, ready for use, by the curved concave lower bearings provided at the bottoms ofthe stationary inclined surfaces H H. In case of any sudden stoppage in the motion of the car or the breaking of the hoisting-rope, the inner end of the levers E E, by their own weight and that of their connections or other weight applied thereto, aided, if desired, by springs 01 d, to make their action more prompt and live ly, are depressed, and their outer ends raised, thereby causing the sudden throwing or jerking upward of the movable friction-blocks F F, and bringing their faces into frictional contact with the faces of the guides b 1), whereby they are caused to remain stationary, and their backs into contact with the free rollers G G. Simultaneously with the raising of the frictionblocks, the car, being unsustained, commences its descent, causing the wider projecting portions of the stationary inclines H H to approach the thicker ends of the friction-blocks their perpendicular position by the hookshaped lips c c which pass behind them, and between which and the friction-blocks they are firmly and securely grasped, sustaining the car until it is raised therefrom by thehoistin g-rope after readjustment. The hoistingrope lifts the car by bringing the inner arms of the levers into contact with the stirrup-like stops h h on the car.

When the rope thus operates to raise the car it does not act through the levers upon the blocks or wedges F F, as the outer ends of the said levers are free to slide down the suspending-rods of the blocks or wedges; but as soon as the weight of the car is taken by the rope,

' and the car begins to ascend, the blocks or and are caused to drop by gravitation to their 7 original position of suspension from the levers.

the T-shaped guides attached throughout their whole length to the guide-posts A A.

2. The combination, with the stationary inclines H H on the platform or cab, the frictionrollers G G and the sliding blocks or wedges F F, and the levers E E, when the connection of the said sliding blocks or wedges with the levers is made by a free connection, substantially as herein described, whereby the sliding blocks or wedges are liberated only by the upward movement of the platform or cab.

3. The combination of the levers E E, the freely-attached sliding blocks orwedges F F, the stops h h on the platform or cab, fixed inclined surfaces H H, the rollers G G, the hookshaped lips c c, and the T-shaped guides b b, the whole arranged and operating substantially as herein set forth.

' WM. D. ANDREWS.

Witnesses:

FRED. HAYNES, R. E. RABEAU. 

